 /*******************************************************************************
  * Copyright (c) 2004, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.osgi.framework.log;

 import java.io.*;
 import org.osgi.framework.FrameworkEvent;

 /**
  * The FramworkLog interface. A FrameworkLog implementation is provided by the
  * FrameworkAdaptor and used by the Framework to log any error messages and
  * FrameworkEvents of type ERROR. The FrameworkLog may persist the log messages
  * to the filesystem or allow other ways of accessing the log information.
  * @since 3.1
  */
 public interface FrameworkLog {
     /**
      * A service lookup constant (value "performance") indicating an
      * implementation of the logging service that logs performance events.
      * Create a filter with this property set to <code>"true"</code> in order to
      * obtain a performance log.
      *
      * @since 3.1
      */
     public static final String SERVICE_PERFORMANCE = "performance"; //$NON-NLS-1$

     /**
      * Logs the information from a FrameworkEvent to the FrameworkLog.
      * @param frameworkEvent The FrameworkEvent to log.
      */
     public void log(FrameworkEvent frameworkEvent);

     /**
      * Logs the FrameworkLogEntry to the FrameworkLog
      * @param logEntry The entry to log.
      */
     public void log(FrameworkLogEntry logEntry);

     /**
      * Sets the current Writer used to log messages to the specified
      * newWriter. If append is set to true then the content
      * of the current Writer will be appended to the new Writer
      * if possible.
      * @param newWriter The Writer to use for logging messages.
      * @param append Indicates whether the content of the current Writer
      * used for logging messages should be appended to the end of the new
      * Writer.
      */
     public void setWriter(Writer newWriter, boolean append);

     /**
      * Sets the current File used to log messages to a FileWriter
      * using the specified File. If append is set to true then the
      * content of the current Writer will be appended to the
      * new File if possible.
      * @param newFile The File to create a new FileWriter which will be
      * used for logging messages.
      * @param append Indicates whether the content of the current Writer
      * used for logging messages should be appended to the end of the new
      * File.
      * @throws IOException if any problem occurs while constructing a
      * FileWriter from the newFile. If this exception is thrown the
      * FrameworkLog will not be effected and will continue to use the
      * current Writer to log messages.
      */
     public void setFile(File newFile, boolean append) throws IOException;

     /**
      * Returns the log File if it is set, otherwise null is returned.
      * @return the log File if it is set, otherwise null is returned.
      */
     public File getFile();

     /**
      * Sets the console log option. If this is set then all logs will be
      * logged to System.out as well as the current Writer.
      * @param consoleLog indicates whether to log to System.out
      */
     public void setConsoleLog(boolean consoleLog);

     /**
      * Closes the FrameworkLog. After the FrameworkLog is closed messages may
      * no longer be logged to it.
      */
     public void close();
 }

